Tsunami of Guidelines: Waves of Controversy Greet New Documents

Dec 17, 2013

CardioSource WorldNews

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The November launch of four sets of guidelines by the ACC and the American Heart Association (AHA) unleashed waves of information on blood cholesterol control, management of overweight and obesity, risk assessment, and lifestyle management—all designed to reduce cardiovascular risk and all focused on answering critical questions for clinical care. At the same time, a science advisory released by the ACC, the AHA, and the Centers for Disease Control (CDC) offered an effective approach to high blood pressure control.

Without a doubt, the greatest amount of ink (i.e., media attention) was spilled over the new guidelines for the treatment of blood cholesterol1 and a related set of guidelines addressing cardiovascular risk assessment.2 The cholesterol guidelines no longer focus on reducing the level of LDL cholesterol to specific targets, but rather concentrate on determining which patients are candidates for statin therapy and the intensity of the therapy used. They also emphasize assessing each patient’s personal risk factors of developing heart disease, including global risk assessment based on 10-year atherosclerotic cardiovascular disease (CVD) risk assessment.

Why not continue to treat to target? The guidelines note major difficulties with this approach, including a lack of randomized clinical trials to indicate what that target should be. The magnitude of additional risk reduction provided by one target over another is also unknown. While it was thought that this de-emphasis on cholesterol targets would elicit some debate, it was an accompanying risk calculator itself that garnered more—and sometimes heated—attention from the press. Indeed, some reports seemed more like coverage of a new reality program, “The Real Housewives of Cardiology,” than a scientific discussion. The New York Times highlighted concerns that the calculator “appears to greatly overestimate risk,” resulting in “turmoil” and “embarrassment” for the ACC and AHA.

Like The New York Times, The Boston Globe cited concerns expressed by Paul Ridker, MD, director of the Center for Cardiovascular Disease Prevention at Brigham and Women’s Hospital in Boston, referring to it as “a high-profile assault on the risk-assessment tool.” Both papers referred to “an emergency meeting” with Dr. Ridker on the Saturday night of the AHA meeting, portraying it as an “unprecedented” (as one reporter put it) effort to fix “a disaster in terms of credibility” (The New York Times again, this time quoting Peter Libby, MD, also of Brigham). Despite the drama depicted in the press, the Saturday night meeting consisted of members of the guidelines committees getting together with Dr. Ridker to discuss his concerns.

Taking a Calculated Risk with the New Risk Calculator?

Once the risk calculator was published online ahead of print, Dr. Ridker and colleague Nancy Cook, ScD, tested it by applying it to more than 100,000 people who had been followed for decades in Brigham-led studies. As they reported days later in a piece published online in the Lancet,3 they found that the calculator overestimated a person’s 10-year risk of having an MI or stroke by 75–150%, based on the study participants who later went on to develop these cardiovascular problems.

In their Lancet piece, Drs. Ridker and Cook wrote that “by eliminating emphasis on LDL treatment targets and the need to measure concentrations of creatine kinase during follow-up, the new guidelines greatly simplify care for the general medicine community. These changes are substantial and will improve patient care.”

They also stated that the risk calculator “systematically overestimated” cardiovascular risks, and could therefore lead to overtreatment of a substantial fraction of the 33 million Americans potentially affected by the guideline. “These concerns call for careful reanalysis before the new guideline goes into effect.”
In response to the concerns, Symphony Health Solutions, known for its health care analytics, conducted a short survey of 150 primary care physicians and cardiologists in the United States and another 100 overseas. They study found that while the potential impact of the new 10-year cardiovascular risk algorithm is generating some debate, most practicing physicians agree with the new guidelines and are already treating their patients in-line with them. As a result, Symphony predicts only a modest 5% increase in the total number of US patients prescribed statins (with an estimated 36 million patients already on statins), although there will likely be a shift towards “high-intensity” statins.

David Goff Jr., MD, PhD, dean of the Colorado School of Public Health and co-chair of the risk assessment working group, said in a press briefing that the CDC says one out of three Americans die from heart disease or stroke and fully 60% of Americans will experience a major cardiovascular event. “We came up with a risk assessment approach that would allow us to identify the individuals at greatest risk in whom our treatments could have the greatest benefit and [that approach] recommends treating about one-third of adults between 40 and 75 [years of age] with statins for primary prevention. So, about one-third of Americans die of heart disease or stroke and we are recommending about one-third of adults be treated with statins for primary prevention. This is comparable to what was recommended in ATP III (the earlier cholesterol guidelines).”

He said the committee used the best available cohort data to develop the risk equations, allowing—for the first time—the development of risk equations specific for African-American populations. “This is a great step forward because in the past we have had to use equations developed for a white population.” Another significant advance, said Dr. Goff, was to add stroke risk assessment. “Many patients will tell you they would rather die than have a major disabling stroke. We think it is very important to estimate risk for stroke to guide [preventive] therapy and this risk equation allows us to do that.”

He added, “We did extensive external validation and this score has been subjected to more external validation than any other score published other than the Framingham score, published in the late 1990s, and the EuroScore.”

Donald Lloyd-Jones, MD, ScM, is chair, Department of Preventive Medicine at Northwestern University’s Feinberg School of Medicine, and co-chair of the risk assessment work group with Dr. Goff. He’s not surprised that the new risk calculator may overestimate risk in participants in the Women’s Health Initiative or the Nurses and Physicians Health Studies, “because these studies contain populations who are healthier than the broader population and have event rates lower than the general population.” The rate of smoking, for example, in nurse and physician participants is about two-thirds lower than the general population.

“The context is really important,” he added. “Our risk assessment guideline does not tell you what to do; it just estimates risk. We would love to see Dr. Ridker’s data, but I suspect the difference is he is looking at extraordinarily healthy cohorts and we’re looking at representative cohorts. The truth is going to be somewhere in the middle. Over time, we’re going to modify these risk scores so that they do better and better and we get closer and closer to our goal of personalized medicine.”

Neil Stone, MD, also of the Feinberg School of Medicine and chair of the cholesterol guideline committee, said, “When we met with Dr. Ridker Saturday night, there was a lot of over-prediction in high-risk groups. The imprecision in that group is not going to make a difference because they would have been recommended for a statin either way. At the other end, the media pointed to some examples of people who had a 7% risk instead of 7.5% risk, but these people are still in a zone of risk and we did not specify that these patients automatically get a statin.” Getting an individual patient’s risk score, he stressed, is the start of the risk discussion and not the end. “We want a patient to ask, ‘How do I know this applies to me?’ It gets the risk discussion going in the area where a decision needs to be made.”

Dr. Goff added, “What is critically important is to be able to rank individuals correctly; that is, people at higher risk are accurately assessed as high risk and those at lower risk are assessed correctly to be lower risk. It would be great to predict risk perfectly, but the most important thing is [the new risk calculator] helps us rank them appropriately. This tool does an excellent job of ranking people as either high risk or lower risk.”

As for the alleged “credibility” issue, Dr. Stone said the guidelines were developed by a group of physician scientists representing a diverse set of interests who tried to align the guidelines with the available scientific evidence. Anything less means we get guidelines representing “the loudest voice in the room and that’s not right. We need guidelines that are based on evidence and then put the patient and physician at the center of this. I want a patient to say to me, ‘Doc, is this right for me?’ and I want to be able to say why I think this makes sense. The guidelines allow physicians and patients to decide for themselves what is appropriate.”

Despite the media reports, in a statement released online via Brigham and Women’s Hospital, Dr. Ridker “strongly supports the key messages of the new guidelines and believes that questions raised about the risk calculator should be relatively easy to address.” He is quoted in the Brigham release: “The new ACC/AHA guidelines for statin therapy have taken several major steps forward that will greatly improve patient care. These include an emphasis on prevention of stroke as well as heart disease, a focus on statin therapy rather than alternative unproven therapeutic agents, and recognition that more intensive statin treatment is superior to less intensive treatment for many patients. Further, the new guidelines greatly simplify care for the general medicine community. It is critical for patients with known heart disease, diabetes, or high levels of LDL-cholesterol to be treated—and treated aggressively.”

While press coverage also questioned the emphasis on statin therapy and value of this approach for primary prevention, Dr. Ridker added, “There are now six major randomized trials demonstrating that statin therapy, in addition to lifestyle improvement, substantially cuts rates of heart attack and stroke. From a public health perspective, we need to make certain that prescribing physicians understand who was treated in the trials, what the data show, and how to translate that knowledge to best care for our patients.”

Translating that knowledge to optimal patient care does not translate to simply “get more people on statins,” said Mariel Jessup, MD, medical director of the Penn Heart and Vascular Center, Philadelphia, and current president of the AHA. “The goal is to get people to reduce their risk. This is why there is a portfolio of four documents. The goal is to get people to live longer.”

According to John Gordon Harold, MD, president of the ACC, clinical practice guidelines such as these should not take the place of sound clinical judgment, but enable a discussion between a patient and their health care provider about the best way to prevent an MI or stroke, based on the patient’s personal health profile and their preferences.

In a joint statement released by the AHA and the ACC, both Drs. Harold and Jessup noted that these guidelines have probably been the most carefully vetted guidelines ever published. “We feel good about these guidelines and right now we are confident that these contain the best evidence so physicians can take care of their patients,” Dr. Jessup said.

The Other Guidelines

Coverage of the risk assessment tool and cholesterol guidelines consumed most of the available media bandwidth—well, reporter attention bandwidth, at least—but the documents were not released in isolation.

The ACC, AHA, and The Obesity Society issued comprehensive treatment recommendations to help health care providers tailor weight loss treatments for adults who are overweight or obese.4 “Weight loss isn’t about willpower. It’s about behaviors around food and physical activity, and getting the help you need to change those behaviors,” said Donna Ryan, MD, co-chair of the writing committee and professor emeritus at Louisiana State University’s Pennington Biomedical Research Center in Baton Rouge.

In the United States, nearly 155 million adults are affected by overweight (defined as a body mass index or BMI of 25–29.9) or obesity (BMI ≥30). The report recommends that health care providers calculate BMI at annual visits or more frequently, and use the BMI cut points to identify adults who may be at a higher risk of heart disease and stroke because of their weight.

Culture promotes supplements and fad diets that promise quick and easy weight loss. It’s important that physicians have authoritative recommendations for managing weight to improve patient health. Most studies recommend a goal of 5–10% weight loss. This is enough to improve blood pressure, lipid profile, and the need for medications to control blood glucose.

Patients often what to know, “What’s the best weight loss program?” The skinny from the guidelines: there is no ideal diet for weight loss and no superiority for any of the myriad diets reviewed. It’s important to choose a diet that considers patient preferences and health status, preferably referring patients to a nutritional professional for counseling. It is also recommended that patients receive a comprehensive program encompassing diet, physical activity, and behavior modification of 6 months or longer. The gold standard is an on-site, high-intensity program (>14 sessions across 6 months) delivered in group or individual sessions by a trained professional. Web-, phone-, or text-based approaches can be used to supplement such a program, or as an alternative when patients can’t access an on-site program.
For the first time, the guidelines discuss bariatric surgery as an option that can be considered for patients with a BMI of ≥40 (or ≥35 if they have one or more cardiovascular comorbidities).

Additionally, a new lifestyle guideline summarizes key nutrition and physical activity topics for the management of blood pressure and blood cholesterol.5According to Robert Eckel, MD, professor of medicine, University of Colorado, Aurora, “Eating a heart-healthy diet is not about good foods and bad foods in isolation from the rest of your diet—it’s about the overall diet.” Co-chair of the committee producing the Lifestyle Management to Reduce Cardiovascular Risk guidelines, Dr. Eckel said the recommendations do not directly address adaptations for a weight loss diet (which is information within the obesity guidelines) but the lifestyle guidelines do provide complementary information that assists overall reduction of calorie intake.

The lifestyle guidelines discuss the Mediterranean diet and the Dietary Approaches to Stop Hypertension (or DASH) diet and its many variations, as well as both high- and low-glycemic diets. There is more emphasis on dietary patterns overall, and more data to support saturated and trans-fat restriction and dietary salt restriction.

Finally, while not a set of guidelines, a new AHA/ACC/CDC science advisory was released,6 too, offering an effective approach to high blood pressure control. The document supports current clinical guidelines and offers updated information that helps improve treatment of patients and control of hypertension. It serves as a call to action for broad-based efforts to improve hypertension awareness, treatment, and control.

The advisory includes a template outlining a general approach for an effective treatment algorithm that is intended to be a critical part of a coordinated, multipronged, systematic approach to controlling hypertension by facilitating clinical decision making and providing a default approach with proven benefits.

The blood pressure goal for most people is <140 mm Hg systolic and <90 mm Hg diastolic, although lower targets may be appropriate for specific populations such as African-Americans, the elderly, and patients with LV hypertrophy, systolic or diastolic LV dysfunction, diabetes, or chronic kidney disease.